We propose studying (a) possible alterations in quinuclidinylbenzilate and alpha-bungarotoxin binding in the striatum after ablations in neural regions providing caudate-putamen afferents in an attempt to assess whether or not putative cholinergic receptors are associated with such striatal afferents. (b) Research will also conducted on the high-affinity cholinergic uptake blocker, SLB-3, in an attempt to develop a viable histochemical method for cholinergic neurons. And (c) a new histochemical method in which the fluorescent probe Evans Blue is used in combination with AChE will be employed to determine whether or not AChE-containing striatal neurons project outside that nucleus.